Nickelback – the fifth defensive back in some sets, such as the nickel formation

Dimeback – the sixth defensive back in some sets, such as the dime formation

The seventh defensive back, in the exceedingly rare "quarter" set, but often strong

known as a dollar back or a quarter back (not to be confused with the offensive player who throws the ball)

The group of defensive backs is known collectively as the secondary.[2] They most often defend the wide receiver corps; however, at times they may also line up against a tight end or a split out running back.